1. Field of the Invention
The present invention relates to a disk drive and a method of controlling the same and, more particularly, to a method and apparatus for determining disk drive parameters in accordance with ambient temperature.
2. Description of the Related Art
Generally, the features of a magneto-resistive write and read head for respectively recording and reproducing, information on a disk of a hard disk drive can be optimized by varying a variety of parameters affecting the performance of the hard disk drive during a burn-in process customarily performed during manufacture of the hard disk drive. That is, values of various parameters corresponding to a channel factor, which optimizes the features of read and write channels, are controlled during the burn-in process.
In a hard disk drive, changes in a head media signal as well as mechanical changes occur due to fluctuations of environmental conditions such as temperature that deleteriously affect the performance of the hard disk drive. For these reasons, I have found that there is a need to correct parameters of the hard disk drive in accordance with changes of temperature. In this regard, Japanese Laid-Open Patent Publication No. Hei 10-340412 discloses an information memory device capable of sensing variations in temperature and attempting to correct the write current to a predetermined value found in a look-up table.
I have found that changes in temperature below the ambient temperature result in changes in the flying height of a head, the magnetic coercive force of a disk, a rate of variation of the resistance of the magneto-resistive (MR) head and non-linear transmission shift (NLTS) of the head. In contemporary practice however, only one parameter of a hard disk drive, namely the write current, is corrected in accordance with variations in the temperature surrounding a hard disk drive; other parameters related to thermal change are maintained at fixed values. Therefore, it is difficult to obtain the optimum performance of the hard disk drive and thus the quality of the performance of the hard disk drive deteriorates.